This invention relates to recycling flush toilet systems. The invention may be used in portable toilet systems, and in other locations where running water is not available or is only available in a limited supply such as aboard airplanes, boats and trailers, or in a basement or a cabin, etc. Conventional portable or transportable toilet units are typically used at construction sites, outdoor public events and various other venues where a running water supply is unavailable. These systems generally comprise a housing within which a waste material storage tank is positioned. A toilet structure is formed on the top of the tank and opens into the tank for gravity collection of toilet waste material and subsequent removal of accumulations of that material from the tank.
The housings of the portable toilet systems are usually made of large sheets of plastic materials which are formed into rear and side walls and a front wall having a doorway and a suitable door, a roof and a floor.
The waste material holding tank which is also formed of plastic material, is normally positioned within the housing and occupies a portion of the floor space. The toilet waste material drops, under the influence of gravity, into the tank where it is accumulated for collection. Typically, the accumulated waste within the holding tank is removed, from time to time, by inserting a pipe, through the toilet opening, into the tank and (vacuuming) pumping the accumulated waste material into a suitable tank-truck for removal of the waste to a waste disposal and processing center.
Examples of known portable toilet units are disclosed in U.S. Pat. No. 3,447,167 Harding, U.S. Pat. No. 3,835,480 to Harding, U.S. Pat. No. 4,031,572 to Harding, U.S. Pat. No. 4,577,351 to Harding, U.S. Pat. No. 4,831,671 to Harding, U.S. Pat. No. 4,918,765 to Harding, and U.S. Pat. No. 3,435,464 to Harding.
Although prior art portable toilet units are satisfactory for their purposes, the public has become accustomed to the use of indoor flush-type toilets, so that flush-type toilets are preferred. Flush toilet systems are more sanitary, less unsightly and reduce the offensive odors associated with non-flush toilets.
Examples of portable flush toilet systems are disclosed in U.S. Pat. No. 5,500,960 to Tagg, U.S. Pat. No. 5,913,610 to Duck and U.S. Pat. No. 6,721,967 to Braxton. One of the drawbacks of portable flush toilet systems is that a fresh water supply is required to enable the flushing mechanism. The fresh water supply is limited by the size of the fresh water tanks supplied. Once the fresh water supply is exhausted, it is necessary to empty the waste tank and replenish the fresh water. It is desirable to provide a flushing system in which the supply of flushable water can be extended to increase the time between servicing without substantially changing the construction of the toilet housing. The invention of the present application addresses these problems and provides an improved fresh flush recycling toilet system.